www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - Re: Converting Fuse headers

reply Jesse Phillips <jessekphillips+D gmail.com> writes:
I have some good news! It works (Simplest test case). I spent several hours
trying to track down where my code translation could be causing problems. And
have concluded that core.sys.posix.sys.stat.stat_t is not correct for my 32bit
Debian Linux machine.

I realize this is a big claim, so I'm going to look into it some more. But to
get my code working I moved the getattr function into a C file and called that
instead of using it from D. I also noticed that the value set to stat_t.st_mode
would not be returned when requesting it back.

Thank you Simen and div0.

1. https://github.com/he-the-great/Fused
Nov 09 2010
parent reply div0 <div0 sourceforge.net> writes:
On 10/11/2010 06:21, Jesse Phillips wrote:

 I have some good news! It works (Simplest test case). I spent several hours
trying to track down where my code translation could be causing problems. And
have concluded that core.sys.posix.sys.stat.stat_t is not correct for my 32bit
Debian Linux machine.

 I realize this is a big claim, so I'm going to look into it some more. But to
get my code working I moved the getattr function into a C file and called that
instead of using it from D. I also noticed that the value set to stat_t.st_mode
would not be returned when requesting it back.

 Thank you Simen and div0.

 1. https://github.com/he-the-great/Fused



Well done, glad you proved me wrong.

It does seem unlikely that size_t is wrong,
though you can test it easily enough:

compile a test C program to see what size it is and compare it to the D 
version:

void main() {
	printf("sizeof: %d", sizeof(size_t));
}

It should be 4 on a 32 bit system & 8 for 64 bit.

-- 
My enormous talent is exceeded only by my outrageous laziness.
http://www.ssTk.co.uk
Nov 10 2010
parent reply Jesse Phillips <jessekphillips+D gmail.com> writes:
div0 Wrote:


 Well done, glad you proved me wrong.
 
 It does seem unlikely that size_t is wrong,
 though you can test it easily enough:
 
 compile a test C program to see what size it is and compare it to the D 
 version:
 
 void main() {
 	printf("sizeof: %d", sizeof(size_t));
 }
 
 It should be 4 on a 32 bit system & 8 for 64 bit.



Hope I didn't say size_t. stat_t, a very complicated struct known as struct
stat in C. I don't know for sure that it is wrong, but at this point it is the
most likely candidate.

Also none of the changes I made related to the question affected the ability of
the program to work (maybe a more complicated one). Just glad I wasn't to far
off in my translation.
Nov 10 2010
parent reply div0 <div0 sourceforge.net> writes:
On 10/11/2010 20:15, Jesse Phillips wrote:

 div0 Wrote:


 Well done, glad you proved me wrong.

 It does seem unlikely that size_t is wrong,
 though you can test it easily enough:

 compile a test C program to see what size it is and compare it to the D
 version:

 void main() {
 	printf("sizeof: %d", sizeof(size_t));
 }

 It should be 4 on a 32 bit system&  8 for 64 bit.



 Hope I didn't say size_t. stat_t, a very complicated struct known as struct
stat in C. I don't know for sure that it is wrong, but at this point it is the
most likely candidate.

 Also none of the changes I made related to the question affected the ability
of the program to work (maybe a more complicated one). Just glad I wasn't to
far off in my translation.



Sorry, me misreading.

You can still do the size check for the stat_t struct as well,
I always double check the size of structs when doing those conversions 
as it's very easy to get it wrong.

-- 
My enormous talent is exceeded only by my outrageous laziness.
http://www.ssTk.co.uk
Nov 10 2010
parent reply Jesse Phillips <jessekphillips+D gmail.com> writes:
div0 Wrote:


 You can still do the size check for the stat_t struct as well,
 I always double check the size of structs when doing those conversions 
 as it's very easy to get it wrong.



Ah, good idea. The test I have planned will be to set some values in the D
struct, and see what is read by the C struct. The size thing will definitely be
a simple give away if it differs.

I might try to use some reflection to see what the structure D creates looks
like, so that it will be easier to compare the D code with the C header. (Lots
of version statements in the D version, might be some macros in C too.)
Nov 10 2010
parent div0 <div0 sourceforge.net> writes:
On 10/11/2010 21:02, Jesse Phillips wrote:

 div0 Wrote:


 You can still do the size check for the stat_t struct as well,
 I always double check the size of structs when doing those conversions
 as it's very easy to get it wrong.



 Ah, good idea. The test I have planned will be to set some values in the D
struct, and see what is read by the C struct. The size thing will definitely be
a simple give away if it differs.

 I might try to use some reflection to see what the structure D creates looks
like, so that it will be easier to compare the D code with the C header. (Lots
of version statements in the D version, might be some macros in C too.)



Also another thing to make life easier, use gcc's only preprocess the 
file option (-E ?) and save the result. That way you can look at the raw 
struct after all the CPP macros have been applied/stripped out.

That's very handy with complicated C structs.

-- 
My enormous talent is exceeded only by my outrageous laziness.
http://www.ssTk.co.uk
Nov 10 2010